This invention relates to a method and apparatus for providing a noncontact, direct reading method of measuring the `R` value or thermal resistance of a structure such as a wall, ceiling, or the like.
Since heat loss is normally measured in BTU's per square foot per hour, it is convenient to use a signal representative number for an `R` value which is representative of the thermal resistance to heat flow to enable energy auditors, insulation contractors, building inspectors, maintenance personnel and the like to measure heat loss in order to provide preventive maintenance and energy management programs. Accordingly, the `R` value or thermal resistance is the standard index for the insulation efficiency of a building or of an insulating material. The measurement of the `R` value normally requires readings of inside and outside temperatures from which the `R` value is computed. No method has been provided for directly reading this value. Prior methods require several temperature measurements and the use of associated graphs in order to provide an estimate of a usable `R` value.